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1.
To clarify the histogenesis and differentiation potential of central neurocytoma, a pathological investigation of seven tumors from three patients was conducted using immunohistochemistry and ultrastructural analysis in addition to systematic in vitro studies. Six tumors were studied immunohistochemically and five were examined ultrastructurally. All cases that were immunostained were positive for synaptophysin in nuclear-free neuropil islands. In five tumors, a few tumor cells, in addition to reactive astrocytes, were positive for glial fibrillary acidic protein (GFAP). Vimentin staining was also positive in a few tumor cells of five specimens. Neurofilament staining was always negative. All cases for which ultrastructure was examined showed various synaptic abnormalities. Cultured cells were subdivided into three distinct tumor cell types: neuronal cells which stained for neurofilament proteins with neurosecretory granules; small flat undifferentiated cells with a high nuclear-cytoplasmic ratio and scant cytoplasmic organelles; and small round or multipolar astrocytic cells with 10-nm intermediate filaments which stained for GFAP. Our tissue culture studies disclosed that cultured neurocytoma cells form a cellular mosaic similar to subependymal plate layers that are composed of mitotically active cells, neurons and glia.  相似文献   
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The recently developed concept of scalarized photons (formally photons of any polarization) is used to analyze the spontaneous and stimulated emission in the uniform magnetic field free-electron laser in the microwave spectral region. In fact, this free-electron laser is the simplest of many other, wiggler and wiggler-free free-electron lasers whose analyses could be done with scalarized photons in the small signal regime and whose physical parameters can be conveniently chosen for radiation to be generated in the microwave spectral region. As to the uniform magnetic field free-electron laser, which is treated here in some detail, with the electron beam energy of up to 10 MeV and the uniform magnetic field of up to 4 Tesla, the radiation (occurring with the fundamental and higher harmonic frequencies) can cover easily a 10 to 10,000 GHz spectral region.  相似文献   
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This paper presents the temperature dependence of the mechanical properties of structural high-strength low-alloy (HSLA) ASTM A709 Gr50 steel (En10025: S355 JO; DIN: ST 52-3U). Engineering stress-strain diagrams at lowered and elevated temperatures are presented. Creep responses for selected constant stresses at selected temperatures are also presented and are fit with a rheological model. Additionally, a relation between impact toughness and fracture toughness is proposed and is validated using results from notch impact tests on a Charpy pendulum impact machine.  相似文献   
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By means of the modification of Medve?’s de-singular method and a result of two-dimensional linear integral inequalities, components-wise (not on some norm) upper bounds are obtained for solutions of a class of nonlinear two-dimensional systems of fractional differential equations. The uniqueness and continuous dependence of the solutions are also discussed here.  相似文献   
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Removal of numerous classes of pharmaceuticals from the municipal and industrial wastewater, using conventional wastewater treatment, is incomplete and several studies suggested that improvement of this situation would require the application of advanced treatment techniques. This is particularly important for the treatment of industrial effluents, released from pharmaceutical industries, which can contain rather high concentrations of antimicrobials. The aim of this work was to evaluate membrane bioreactors (MBRs), nanofiltration, reverse osmosis and ozonation, as well as their combinations, for the removal of antimicrobials from a synthetic wastewater which simulated highly contaminated industrial effluents. The study was performed using a mixture of four important classes of antimicrobials, including sulfonamides (SA), fluoroquinolones (FQ), macrolides (MAC) and trimethoprim (TMP). Performance of two different types of MBRs, Kubota and Zenon, was evaluated under different regimes regarding hydraulic retention time, total organic load and total nitrogen load. It was shown that elimination of SA in MBR treatment was very efficient, while the elimination of MAC, FQ, and TMP was incomplete. A mass balance of these contaminants in MBR suggested that microbial transformation represented the main mechanism, while only a small percentage was eliminated from the aqueous phase by adsorption onto sludge particles. Nanofiltration and reverse osmosis achieved high elimination rates however produced highly contaminated concentrate. High removal was achieved using ozonation, but further research is needed to characterize formed ozonation products.  相似文献   
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This work focuses on techno-business analysis of service platforms and service portfolios. Service platform (SP) hosts services and enabling service functionality. Service providers deliver two main products: end-user services to their customers and enablers to other business actors. 3rd party service providers combine enablers with their own functionality, wrap them in end-user services and deliver them to their customers.  相似文献   
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